The Alcohol Epidemiologic Data System (AEDS), operated by Cygnus Corporation under contract to NIAAA, serves as a centralized, national repository of alcohol-related data sets. The mandate of the data system is to identify, acquire, and analyze alcohol- related epidemiologic data under the direction of NIAAA's Division of Biometry and Epidemiology. AEDS primary collects data sets which are national in scope. However, some specialized data sets are also included in AEDS. AEDS serves to support the activities of the Division of Biometry and Epidemiology. It produces several reports based on its research activities including a data directory which is a listing and description of major data sets which AEDS staff consider to be of potential value to alcoholism researchers, policy makers and other health professionals.